A father-of-three who considered euthanasia when battling against a spinal tumour has voiced his concern at proposals to change the law.
Peers will vote on changing the rules surrounding euthanasia
Peers will vote this week on a private members' bill allowing a terminally-ill adult to ask a doctor to help them die.
Campaign organisation Dignity In Dying is supporting change, but another group, Care Not Killing, is opposed.
David Williams, 51, from Cardiff, has added his support to protests after a 16-year fight against cancer.
Mr Williams was diagnosed with a tumour on his spine in 1990. It left him in "excruciating pain" and he said he seriously considered euthanasia.
"I was 35 at the time and they (the surgeons) brought me down and said, 'In two years you will probably be in a wheelchair and you probably won't reach 40,' " he said.
"It was a bit of a bolt out of the blue really."
Mr Williams described the six months after the operation as stressful for himself and his family as he went for palliative care.
"I went there and within about three or four days I was a completely different person, bearing in mind I'd suffered horrific weight loss and excruciating pain, sickness and whatever.
"While I was in all sorts of pain and agony it was very clear to me the distress I was causing the family, especially with Lynne just having (had) the baby and having two children I did consider euthanasia.
"It was an option at the time because of the pain. But having said that, having children and the baby I said 'no, I'm going to fight this,' and I am glad that I have done that."
Mr Williams, who uses a wheelchair and whose wife has died, feared euthanasia would be used "for the wrong reasons".
He said: "And you have all sorts of other issues coming into it then and, dare I say it, families will get involved and I think it would be wrong.
"You have to be really clear and until you actually get to the edge which I was, it's very difficult for people on the outside to see it and understand it."
The campaign for a change in the law surrounding the issue of euthanasia is being supported by the group Dignity in Dying which was formally known as the Voluntary Euthanasia Society.
Its patron is Brian Pretty, the widower of the late Diane Pretty, who died of motor neurone disease.
Mrs Pretty took her fight for the right to die to the European Court of Human Rights,and died in 2002.
The society said it would continue to campaign for people's rights to choose how they want to die.